Builders or contractors often install an exterior door using a pre-hung door. As shown in FIG. 1, a typical pre-hung door 10, includes a frame 12 and a door panel 14. The frame 12 typically includes a threshold 16, a header 18, a latch-side jamb 20, and a hinge-side jamb 22. A plurality of hinges (not shown) generally mount the door panel 14 to the hinge-side jamb 22. The pre-hung door 10 may then be installed within a rough opening 24 of an enclosure defined by at least a pair of studs 26 and a cross beam 28. Sheathing 30, such as oriented strand board (OSB) or plywood, may be applied around the rough opening 24 adjacent to the exterior thereof, and sheet rock (not shown) may be applied around the interior of the rough opening.
Pre-hung doors 10, also referred to as door units, are often preferred over separately hanging slab doors, especially for exterior entryways. Pre-hung doors 10 may be preferred because they are pre-assembled to provide a tight fitting, substantially watertight, seal between the frame 12 and the door panel 14. Pre-hung doors 10, however, can lack rigidity prior to installation. Thus, portions of pre-hung doors 10 have been found to bend, bow, twist, expand, contract, or otherwise shift during shipping, handling, and installation. These changes can reduce the quality of the pre-assembled seal between the frame 12 and the door panel 14. Returning to proper alignment and spacing between the door panel 14 and the surrounding frame 12 can be highly dependent upon installation practices and the skill of the installers.
To support and position the pre-hung door 10 within the rough opening 24, wooden tapered shim pairs are conventionally used between the frame 12 and the studs 26 or cross beam 28. The tapered shim pairs may be used at several locations around the frame 12 to correspond with locations where the frame 12 is fastened to the rough opening 24.
There remains a need for an adjustable shim capable of adding support between the outside face of the frame 12 and an opposing inside face of the studs 26 or cross beam 28, such that a pre-hung door 10 may be more easily and accurately supported and positioned within a rough opening 24.